As soon as vet Matthew Fry shaved the dog's leg ready for the needle, Lizzie started feeling faint.

But seconds after Daisy was given the killer dose, Lizzie started making loud, strained noises before she stopped breathing, collapsed on the floor and turned blue.

Wasting no time Matthew, got nurse Sarah Mainwaring to give her oxygen and dial 999, while he performed life-saving CPR.

Life-saver: Matthew Fry sprang into action when Lizzie Bevis had a heart attack in his surgery (Image: Newsteam / SWNS)

He said: "It seemed like a normal consulting day and Daisy was brought in for a consultation.

"Sometimes clients get a bit upset if there's bad news or something.

"But unfortunately in this case I thought Lizzie had just fainted, but unfortunately we realised she hadn't actually fainted, she'd had a heart attack.

"At that point things really went into high gear."

He added: "Obviously doing CPR on an animal is quite important, but the consequences with a person are much more improtant.

"That day Lizzie's mother was there and Lizzie's sister was also there.

Beloved hound: The shock of seeing Daisy the Jack Russell being put down was too much for Lizzie (Image: SWNS)

"So we were quite conscious that the family members were there."

Paramedics arrived in minutes and rushed Lizzie to Lincolnshire Hospital on July 13, where she was put into a medically induced coma for two days.

She was transferred to Nottingham City Hospital's Acute and Cardiac Unit on July 17 where they discovered Lizzie suffers from Long QT syndrome, a rare heart condition where stress can induce irregular heartbeats that can prove fatal.